I and some fellow jumpers/nerds who are into ham radio have put together gear that posts inflight jump data to the Internet in real time using the APRS packet radio system. We broadcast GPS altitude position course and ground speed. We also post heart rate and blood oxygen % (SpO2). If you click on the red dots you'll see data. Only some of the dots have heart info so try a few.

We will be tweaking and repackaging the Recon HUD gear. Hope to be able to integrate it into a full face helmet.

We've also had success in live air to ground video using ham radio microwave frequencies.

We also built and test flew HF data beacon gear capable of reaching hams many thousands of miles away. Still tweaking this gear. It uses a trailing wire end fed dipole antenna deployed after opening and jettisoned before landing.

Is this stuff practical? We don't really care. We just like making and operating it.